/* YUNLAB — 신뢰감 있는 교육 회사: 짙은 남색 + 따뜻한 금색, 제목은 명조 */
:root {
  --bg: #f7f5f0; --surface: #ffffff; --ink: #14213d; --muted: #55607a; --line: #e4dfd3;
  --navy: #12264f; --navy-2: #1d3a73; --on-navy: #f3f5fa; --on-navy-muted: #b9c3d9;
  --gold: #a87a22; --gold-bright: #d4a64a; --gold-soft: #f3e9d2;
  --serif: "Noto Serif KR", "Nanum Myeongjo", "AppleMyungjo", serif;
  --sans: "Noto Sans KR", -apple-system, "Apple SD Gothic Neo", "Malgun Gothic", system-ui, sans-serif;
  --radius: 14px; --shadow: 0 1px 2px rgba(18,38,79,.06), 0 8px 24px rgba(18,38,79,.07);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0c1220; --surface: #131b2e; --ink: #e9edf5; --muted: #a3adc2; --line: #243049;
    --navy: #0a1630; --navy-2: #12264f; --on-navy: #eef1f8; --on-navy-muted: #9fabc6;
    --gold: #d9b15c; --gold-bright: #e6c272; --gold-soft: #2a2414;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.25);
    color-scheme: dark;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.75 var(--sans);
  word-break: keep-all; overflow-wrap: anywhere; -webkit-font-smoothing: antialiased; }
a { color: inherit; }
img { max-width: 100%; display: block; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }
.serif { font-family: var(--serif); }

/* 머리말 */
.top { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--surface) 92%, transparent);
  backdrop-filter: saturate(1.4) blur(8px); border-bottom: 1px solid var(--line); }
.top .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.mark { width: 34px; height: 34px; border-radius: 9px; background: var(--navy); color: var(--gold-bright);
  display: grid; place-items: center; font: 700 17px/1 var(--serif); }
.brand b { font: 700 18px/1 var(--sans); letter-spacing: 1.5px; color: var(--ink); }
.brand small { display: block; font-size: 11px; color: var(--muted); letter-spacing: .5px; margin-top: 3px; }
.top nav { display: flex; gap: 22px; }
.top nav a { text-decoration: none; color: var(--muted); font-size: 15px; font-weight: 500; }
.top nav a:hover { color: var(--ink); }

/* 첫 화면 */
.hero { background: var(--navy); color: var(--on-navy); position: relative; overflow: hidden; }
.hero::before { content: ""; position: absolute; inset: 0; opacity: .5; pointer-events: none;
  background-image: linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px);
  background-size: 44px 44px; mask-image: radial-gradient(ellipse at 75% 30%, #000 10%, transparent 70%); }
.hero .wrap { position: relative; padding-top: 88px; padding-bottom: 128px; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; color: var(--gold-bright); font-size: 13px;
  font-weight: 700; letter-spacing: 2px; text-transform: uppercase; }
.eyebrow::before { content: ""; width: 28px; height: 1px; background: currentColor; }
.hero h1 { font: 700 clamp(32px, 5.4vw, 54px)/1.28 var(--serif); margin: 18px 0 20px; letter-spacing: -.5px; }
.hero h1 em { font-style: normal; color: var(--gold-bright); }
.hero p.lead { color: var(--on-navy-muted); font-size: 18px; max-width: 600px; margin: 0; }
.hero p.en { color: var(--on-navy-muted); opacity: .8; font-size: 14px; margin-top: 14px; max-width: 600px; }

/* 세 분야 */
.pillars { position: relative; margin-top: -76px; display: grid; gap: 16px; grid-template-columns: repeat(3, 1fr); }
.pillar { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 24px 24px 22px; text-decoration: none; display: block; transition: transform .15s, border-color .15s; }
.pillar:hover { transform: translateY(-2px); border-color: var(--gold); }
.pillar .num { font: 700 13px/1 var(--serif); color: var(--gold); letter-spacing: 1px; }
.pillar h3 { font: 700 21px/1.3 var(--serif); margin: 10px 0 6px; }
.pillar p { margin: 0; color: var(--muted); font-size: 14.5px; }
.pillar .go { display: inline-block; margin-top: 12px; font-size: 14px; font-weight: 700; color: var(--gold); }

/* 섹션 */
section.block { padding: 84px 0 8px; scroll-margin-top: 64px; }
.sec-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 16px; margin-bottom: 26px;
  border-bottom: 1px solid var(--line); padding-bottom: 16px; }
.sec-head h2 { font: 700 30px/1.25 var(--serif); margin: 6px 0 0; }
.sec-head p { margin: 0; color: var(--muted); font-size: 15px; max-width: 460px; }
.kicker { font-size: 12.5px; font-weight: 700; letter-spacing: 2px; color: var(--gold); text-transform: uppercase; }

.grid { display: grid; gap: 18px; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
.item { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px;
  display: flex; gap: 18px; align-items: flex-start; }
.item .thumb { width: 72px; height: 72px; border-radius: 16px; flex: none; object-fit: cover; }
.cover { width: 64px; height: 84px; flex: none; border-radius: 4px 8px 8px 4px; background: var(--navy);
  color: var(--gold-bright); display: grid; place-items: center; font: 700 13px/1.3 var(--serif); text-align: center; word-break: keep-all;
  padding: 6px; box-shadow: inset 5px 0 0 rgba(255,255,255,.12); }
.item h3 { margin: 0; font-size: 18px; font-weight: 700; }
.item .sub { font-size: 13px; color: var(--gold); font-weight: 700; margin: 2px 0 6px; }
.item p { margin: 0; color: var(--muted); font-size: 14.5px; }
.status { display: inline-block; font-size: 12px; font-weight: 700; padding: 2px 9px; border-radius: 999px; margin-left: 6px;
  vertical-align: 2px; background: var(--gold-soft); color: var(--gold); white-space: nowrap; }
.status.on { background: color-mix(in srgb, #2f8f5b 14%, transparent); color: #2f8f5b; }
.item .links { margin-top: 12px; display: flex; flex-wrap: wrap; gap: 8px; }
.btn { display: inline-block; padding: 8px 15px; border-radius: 9px; background: var(--navy); color: var(--on-navy);
  text-decoration: none; font-weight: 700; font-size: 14px; border: 1px solid var(--navy); }
.btn.line { background: transparent; color: var(--ink); border-color: var(--line); }
.btn:hover { filter: brightness(1.12); }
.item.soon { border-style: dashed; background: transparent; }
.item.soon h3 { color: var(--muted); }

/* 원칙 */
.values { display: grid; gap: 0; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--surface); overflow: hidden; }
.value { padding: 26px 22px; border-right: 1px solid var(--line); }
.value:last-child { border-right: 0; }
.value b { font: 700 28px/1 var(--serif); color: var(--gold); display: block; margin-bottom: 12px; }
.value h3 { margin: 0 0 6px; font-size: 17px; }
.value p { margin: 0; color: var(--muted); font-size: 14.5px; }

/* 문의 */
.contact { margin-top: 84px; background: var(--navy); color: var(--on-navy); border-radius: 18px; padding: 40px;
  display: flex; align-items: center; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.contact h2 { font: 700 26px/1.3 var(--serif); margin: 0 0 6px; }
.contact p { margin: 0; color: var(--on-navy-muted); }
.contact .btn { background: var(--gold-bright); color: #1a1405; border-color: var(--gold-bright); font-size: 15px; padding: 12px 20px; }

/* 꼬리말 */
footer { margin-top: 72px; border-top: 1px solid var(--line); background: var(--surface); }
footer .wrap { padding-top: 32px; padding-bottom: 48px; color: var(--muted); font-size: 13px; line-height: 1.85; }
footer .biz b { color: var(--ink); font-size: 14px; }
footer .links { margin-top: 10px; display: flex; flex-wrap: wrap; gap: 16px; }
footer .links a { color: var(--ink); text-decoration: underline; text-underline-offset: 3px; }
footer .copy { margin-top: 12px; }

/* 앱 소개 페이지 */
.page-hero { background: var(--navy); color: var(--on-navy); }
.page-hero .wrap { padding-top: 56px; padding-bottom: 56px; display: flex; gap: 28px; align-items: center; }
.page-hero img { width: 104px; height: 104px; border-radius: 24px; flex: none; }
.page-hero h1 { font: 700 clamp(30px, 5vw, 44px)/1.2 var(--serif); margin: 10px 0 10px; }
.page-hero p { margin: 0; color: var(--on-navy-muted); }
.shots { display: grid; gap: 14px; grid-template-columns: repeat(4, 1fr); }
.shots img { width: 100%; height: auto; border-radius: 16px; border: 1px solid var(--line); box-shadow: var(--shadow); }
.note { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 24px; }
.note ul { margin: 0; padding-left: 20px; color: var(--muted); }
.note li { margin: 6px 0; }
.fine { color: var(--muted); font-size: 13px; margin-top: 20px; }

@media (max-width: 860px) {
  .pillars { grid-template-columns: 1fr; }
  .values { grid-template-columns: 1fr 1fr; }
  .value:nth-child(2) { border-right: 0; }
  .value:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .shots { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 560px) {
  .top nav { gap: 14px; }
  .top nav a { font-size: 14px; }
  .top nav a.hide-s { display: none; }
  .brand small { display: none; }
  .hero .wrap { padding-top: 56px; padding-bottom: 108px; }
  .sec-head { flex-direction: column; align-items: flex-start; }
  .grid { grid-template-columns: 1fr; }
  .values { grid-template-columns: 1fr; }
  .value { border-right: 0; border-bottom: 1px solid var(--line); }
  .value:last-child { border-bottom: 0; }
  .contact { padding: 28px 22px; }
  .page-hero .wrap { flex-direction: column; align-items: flex-start; }
}
@media (prefers-color-scheme: dark) {
  .btn { background: var(--gold-bright); border-color: var(--gold-bright); color: #1a1405; }
  .btn.line { background: transparent; color: var(--ink); border-color: var(--line); }
  .item .cover, .mark { box-shadow: inset 0 0 0 1px rgba(255,255,255,.14); }
}

/* 교재 상세: 표지 · 탭 · 수업자료 목록 */
img.cover { object-fit: cover; padding: 0; }
.cover.big { width: 120px; height: 160px; font-size: 22px; border-radius: 6px 12px 12px 6px; flex: none; }
.btn.gold { background: var(--gold-bright); border-color: var(--gold-bright); color: #1a1405; }
.tabs { display: flex; gap: 6px; border-bottom: 1px solid var(--line); margin-top: 28px; }
.tabs button { font: 700 16px/1 var(--sans); color: var(--muted); background: none; border: 0; padding: 14px 18px;
  border-bottom: 3px solid transparent; margin-bottom: -1px; cursor: pointer; }
.tabs button small { font-size: 12px; color: var(--gold); margin-left: 2px; }
.tabs button[aria-selected="true"] { color: var(--ink); border-bottom-color: var(--gold); }
.tab-panel { padding: 28px 0 8px; }
.tab-panel > p { color: var(--muted); max-width: 720px; margin: 0 0 14px; }
table.info { border-collapse: collapse; margin-top: 18px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
table.info th, table.info td { text-align: left; padding: 10px 18px; border-bottom: 1px solid var(--line); font-size: 15px; }
table.info th { color: var(--muted); font-weight: 500; width: 120px; }
ul.mats { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.mat { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.mat b { font-size: 16px; }
.mat .type { font-size: 12px; font-weight: 700; color: var(--gold); margin-left: 8px; }
.mat p { margin: 4px 0 0; color: var(--muted); font-size: 14px; }
.mat .btn { flex: none; }
.empty { padding: 80px 20px; }
@media (max-width: 560px) { .mat { flex-direction: column; align-items: flex-start; } }

.page-hero .cover.big { background: var(--gold-bright); color: var(--navy); box-shadow: inset 8px 0 0 rgba(0,0,0,.12), 0 10px 30px rgba(0,0,0,.25); }